Is Moderna Covid-19 shot effective against Delta variant? What lab study finds

Moderna Inc's Covid-19 vaccine showed promise against the Delta variant first identified in India in a lab study, with a modest decrease in response compared to the original strain, the drugmaker said on Tuesday.

The study was conducted on blood serum from eight participants obtained one week after they received the second dose of the vaccine, mRNA-1273.

The vaccine provoked an antibody response against all the variants tested, according to Moderna, but one that remained inferior in all cases to the vaccine's neutralising activity against the original coronavirus strain first found in China.

The vaccine was far more effective in producing antibodies against the Delta variant now causing concern than it was against the Beta variant first identified in SA, the data showed.

Against three versions of the Beta variant, the vaccine-elicited neutralising antibodies reduced six-to-eight fold compared to those produced against the original strain, while modest 3.2 to 2.1 fold reductions were seen for lineages of the variant first identified in India, including Delta and Kappa.

“These new data are encouraging and reinforce our belief that the Moderna Covid-19 vaccine should remain protective against newly detected variants,” CEO Stéphane Bancel said.

Earlier in the day, India granted permission to drugmaker Cipla Ltd to import Moderna's vaccine to the country for restricted use.

The drugmaker's shares were up 5.5% at $235.39 (about R3,366) in midday trading.

Moderna has submitted the data as a preprint to the website bioRxiv before peer review.